| 摘要 |
PURPOSE:To etch a film to be etched in a taper form using a vertical photo resist pattern, by isotropic- or semi-isotropic-etching a etching mask, and at the same time by directed-etching the film to be etched. CONSTITUTION:On a film 12 to be etched (a portion of a silicon substrate or a polysilicon film) over the substrate 11, a photo resist film 13 with a vertical cross sectional shape is formed. Next, reactive ion etching is done using SF6+O2 gas. By selecting a concentration of O2 in the etching gas at a appropriate value (about 50%), a film 12 to be etched can be directed-etched and the photo resist 13 can be isotropic- or semi-isotropic-etched. In this way, by employing the photo resist film 13 with a vertical cross sectional shape, the film 12 can be formed in a taper shape 12a. Moreover, by controlling an O2 concentration, cross sectional shape of the processed face can be controlled precisely. |
